A free neutron decays in a lifetime of about $880\,\mathrm{s}$.
Although the neutron lifetime is an important parameter in modern physics,
there is a $4.6\sigma$ ($9.5\,\mathrm{s}$) discrepancy between the experimental results
of two typical methods: the beam method and the storage method.
We are carrying out a new experimental method to measure the neutron lifetime
using a pulsed neutron beam at J-PARC MLF BL05
to determine the cause of the discrepancy,
whether overlooked systematic uncertainties or new physics.
A review of our experiment including the first physics result
with acquired data during 2014 - 2016 and
the status using new neutron optics are presented here.